15. The distance a car travels can be found using the formula d= r. t, where d is distance, r is the rate of speed, and t is time. If the car has traveled 120 miles in 3 hours, what is the average rate of speed?

A. 30 miles per hour

B. 40 miles per hour

C. 60 miles per hour

D. 360 miles per hour

Option B. 40 miles per hour

Step-by-step explanation:

Distance = rate of speed ×  time

If Distance = 120 miles and time = 3 hours

we will have

120 = r × 3

120 = 3r

Divide both sides by 3 and we will have

3r/3 = 120/3

r = 40

rick has $1400 and sally has $1500

step-by-step explanation:

to find amount of money rick has after 10 years :

principal = $1000 , time = 10 years , rate = 4% annually

to find amount of money sally has after 10 years :

her friend gives to pay her $50 per year, therefore money she has after 10 years = 50 × 10 = $500

also, sally gets $1000 after 10 years,

therefore, total amount of money sally has after 10 years = 500 + 1000 = $1500

so, after 10 years : rick has $1400 and sally has $1500